Centerless grinding machine



June 9, 1959 9 l.. coEs, JR 2,889,666

CENTERLESS GRINDING MACHINE Filed Dec. 5l, 1956 2 Sheets-Sheet 1HTTOZNEY June 9, 1959 l.. GOES, JR 2,889,666

CENTERLESS GRINDING MACHINE Filed Dec. 31, 1956 2 Sheets-Sheet 2INVENTOR 0R/NG C055 Je.

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/TTOENEY CENTERLESS GRINDING MACHINE Loring Cees, Jr., Worcester, Mass.,assigner to Norton Company, Worcester, Mass., a corporation ofMassachnsetts Application December 31, 1956, Serial No. 631,828

4 Claims. (Cl. 51-129) The invention relates to grinding machines andmore particularly to a high speed centerless grinding machine. Thisinvention relates to an improvement over my centerless grinding machinedisclosed in my co-pending application Ser. No. 621,365, filed November9, 1956.

One object of the invention is to provide a simple and thoroughlypractical high speed centerless grinding machine. Another object is toprovide a grinding wheel supporting and rotating mechanism for agrinding wheel having a plane operative face in which an outboardbearing support is provided for the wheel spindle to facilitateoperation at high speeds. Another object is to provide a verticaladjustment for the grinding wheel so as to provide either a singlegrinding station or a pair of spaced grinding stations.

Another object is to provide a regulating wheel arrangement including apair of spaced regulating Wheels for supporting and rotating work piecesat the entrance and discharge ends of the grinding throat. Anotherobject is to provide a pair of spaced regulating wheels on a rotatablespindle which are adjustable in an axial direction to facilitatepositioning the regulating wheels so as to support and rotate Workpieces entering and leaving the grinding throat in any adjusted positionof the grinding wheel either when positioned for use as a singlegrinding station or as two spaced grinding stations. Another object ofthe invention is to provide suitable adjustments for the regulatingwheel so that it may be adjustably swivelled, both in a horizontal and avertical plane. Other objects will be in part obvious or in part pointedout hereinafter.

In the accompanying drawings in which is shown one of variousembodiments of the mechanical features of this invention:

Fig. 1 is a front elevation of the centerless grinding machine, havingparts broken away and shown in section;

Fig. 2 is a plan view of the machine;

Fig. 3 is a right hand end elevation of the machine, taken approximatelyon the line 3-3 of Fig. 2, with the regulating wheel assembly removed so'as to more fully illustrate the relationship of the grinding wheel andwork rest;

Fig. 4 is a fragmentary sectional view, mately on the line 4-4 of Fig. 2through wheel assembly;

Fig. 5 is a fragmentary detail view, on an enlarged scale, of the swiveladjusting mechanism for the regulating wheel;

Fig. 6 is a fragmentary sectional view, on an enlarged scale, showingthe mounting and axial adjusting mechanism for the regulating wheel; and

Fig. 7 is a fragmentary elevation showing the relationship of thegrinding wheel, spaced regulating wheels, and work rest when thegrinding wheel is raised vertically to its uppermost position.

A centerless grinding machine has been illustrated in the drawingscomprising a base 10 which supports a transversely movable slide 11 on adovetail slideway 12 formed taken approxithe regulating 2,889,666Patented June 9, 1959 2 on the upper surface of the base 10. A feedingmechanism is provided for adjusting the slide 11 comprising a rotatablefeed screw 13 which is rotatably journalled in a bracket 14 fastened tothe left hand end of the machine base 10. The feed screw 13 meshes withor engages a threaded aperture 15 formed with the slide 11. A manuallyoperable feed wheel 16 is provided for actuating the feed screw 13 forpositioning the slide 11.

The transversely movable slide 11 serves as a support for a verticallyadjustable wheel slide 20 which is arranged to slide vertically on adovetail slideway 21 formed on a vertically extending projection 22 ofthe slide 11. The wheel slide 11 serves as a support for a rotatablewheel spindle 23 which is journalled in suitable bearings (not shown)for rotation at a relatively high speed. The Wheel spindle 23 supports agrinding wheel unit 24, to be hereinafter more fully described.

A driving mechanism is provided for rotating the wheel spindle 23 at arelatively high speed comprising an electric motor 25 which isadjustably mounted on the upper surface of the wheel slide 20. The motor25 is provided with a motor shaft 26 which supports a multipleV-groovepulley 27. The pulley 27 is connected by multiple V-belts 28with a multiple V-groove pulley 29 mounted on the left hand end of thewheel spindle 23 (Fig. l)

A feeding mechanism is provided for adjusting the vertical slide 20 tofacilitate positioning the grinding Wheel unit 24. This mechanismcomprises a feed screw 30 (Figs. 1 and 2), the upper end of which isrotatably sup- .ported by a plate 31 mounted on the upper surface of thevertical projection 22 of the slide 11. The plate 31 is provided with :abearing rotatably to support the upper end -of the feed screw 30. Thelower end of the feed screw 30 is supported by an anti-friction endthrust bearing 32 which is mounted on the transversely movable slide 11.The feed screw 30 meshes or engages a nut 33 which is xedly mounted onthe vertically movable slide 20.

The wheel slide 11 is also provided with a vertical cylindricalguidepost 34 the lower end of which is fastened to the slide 11. Theslide 20 is provided with a projecting boss 35 having a cylindrical hole36 therein which mates with the rod 34 and serves to support and guidethe slide 20 as it is adjusted vertically by a rotary motion of the feedscrew 30.

The grinding wheel unit 24 is arranged to support segment type wheelwith only a relatively short portion of the segments projecting toprovide a wheel capable vof rotating at high speeds. As illustrated inFig. 1, a wheel supporting plate 40 is mounted on a reduced portion 41of the wheel spindle 23 and is held thereon by lock nuts 42. A pluralityof bonded abrasive segments 43 are fastened to the plate 40 by screws44. In order to support the segments against centrifugal force at highspeeds, the segments are surrounded by a cupshaped support 45 which isslidably keyed onto a threaded portion 46 of the wheel spindle 23. Theinternal surface of the cup-shaped support 45 is provided with aplurality of integral lugs 47. The lugs 47, as illustrated in Fig. 3 arepreferably dovetail in shape and mates with grooves cut in the adjacentedge portions of adjacent segments. As illustrated in Fig. 1, theabrasive segments project from the right hand end of the support 45 onlya-relatively short distance so that the segments are supported towithstand centrifugal forces at high speed.

It is desirable to provide an adjustable support for the cup-shapedmember 45 so that as the plane operative face of the segments wear awaydue to grinding, the cup-shaped support 45 may be adjusted toward theleft (Fig. 1) to expose a desired portion of the segments,

- position.

"l and 2).

In order to facilitate an axial adjustment of the member 45, a spannertype lock nut 48 is provided on the threaded portion 46 of the spindle23. A cup-shaped nut 49 is also threaded onto the threaded portion 46 ofthe spindle 23 and is provided with a plurality of radially projectingpins 50 (only one'of which is illustrated in Fig. l) which ride in agroove formed in a hub portion 51 of the cup-shaped support 45. When itis desired to adjust the cup-shaped support 45 to expose a new portionof the segments after wheel wear, the lock nut 43 is backed-off afterwhich the collar 49 is rotated to axialiy adjust the position of thecup-shaped support 45. After the member 45 has been adjusted, the locknut 48 is again tightened to lock Vthe member 45 in the new position.

In order to provide a more rigid support for the wheel spindle 23adjacent to the plane operative face 65 of the grinding wheel when thespindle is rotated at high speeds, an outboard bearing 60 is provided tosupport a reduced end portion 61 of the Wheel spindle 23. The bearing 60is supported by a downwardly extending arm 62 which is fastened to astud 63 carried by a bracket 64 which is formed either integrally orfixe'dly mounted onto the wheel slide 20. If desired to facilitatechanging wheel segments, the arm 62 supporting the `outboard bearing 60may be unclamped from the stud 63 and removed therefrom.

The base is provided with an upwardly extending projection 70 having anupper plane surface 71 which .serves as a support for an angle ironbracket 72 (Figs. 1 and 3). The angle iron bracket 72 serves as asupport for a work rest blade 73.

The angle iron bracket 72 is supported by a vertically yarranged pivotstud 74 to facilitate an angular adjustment of the work rest blade 73 ina horizontal plane relative to the plane annular face 65 of the grindingwheel. A pair of spaced clamping screws 75 and 76 --(Fig. 3) passthrough elongated slots or enlarged holes 77 and 78, respectively, inthe angle iron bracket 72 and are screw threaded into the upwardlyextending projecting 70 of the base 10.

A plurality of clamping screws 79, 80, 81, and 82 pass through spacedvertically-arranged elongated slots Y83, 84, 85, and 86, respectively,formed in the angle iron bracket 72 and are screw threaded into the workrest blade 73. `It will be readily apparent from the foregoingdisclosure that by loosening the clamping screws '75 and 76, the workrest blade 73 may be `swivelled into the desired position vrelative tothe operative face of the abrasive segments 43 after which the clampingscrews may be tightened to lock the bracket 72 in adjusted position. Thework rest blade 73 may be adjusted vertically relative to the grindingwheel unit 24 by means of loosening the clamping screws 79, 80, 81 and82 and Athen adjusting the plate 73 vertically relative to the bracket72 after which the clamping screws may again be tightened to lock thework rest blade 73 in adjusted The work rest blade 73 is provided with abevelled work engaging and supporting surface 87 (Figs. v1 and 3).

The base 10 serves as a support for a transversely movable regulatingwheel slide 95 which supports a regulating wheel unit 96. The slide 95is arranged to slide along a dovetailed slideway 97 formed on the uppersurface of the base 10.

A feeding mechanism is provided for the slide 95 comprising a rotatablefeed screw 98 which is rotatably supported by a bracket 99. The bracket99 is iixedly mounted on the right hand end of the base 10 (Figs. Thefeed screw 98 Vmeshes with or engages a nut 100 depending from theunderside of theregulating lwheel slide 95. A manually operable feedwheel 101 is mounted on the `right 'hand end of the feed screw '98 vtofacilitate rotating `thefeed screw -98 in either direction to cause atransverse adjustment of the slide relative to the base 10.

The slide 95 is provided with an upwardly extending cylindrically-shapedcolumn 105 which supports a frame 106. T'ne frame 106 is provided withan internal cylindrical bore 107 which mates with the outer peripheralsurface of the column 105. The frame 106 is provided with a slot 108 anda clamping screw 109 by means of which the frame 106 may be clamped inan adjusted position on the column 105 in adjusted position relative tothe slide 95. This mounting just described serves to facilitateswivelling the regulating wheel unit in a horizontal plane about thevertical axis of the column 105.

The frame 106 serves as a support for a relatively large trunnion 110.The regulating wheel unit is arranged to iit over the frame 106 and isprovided with a cylindrical bore 112 which mates with the outerperipheral surface of the trunnion 110. A screw adjusting mechanism isprovided for swivelling the regulating wheel unit in a vertical planeabout the horizontal .axis of the trunnion 110. These swivellingadjusting mechanisms have been illustrated in Fig. 5 and comprises apair of spaced blocks 116 and 117 which are iixedly screwed onto theregulating wheel unit 111. The blocks 116 and 117 support a pair ofopposed axially aligned adjusting screws 118 and 119 respectively whichare arranged to engage opposite sides of a stud mounted on the frame106. By manipulation of the screws 118 and 119,'the regulating wheelhead 111 may be swivelled about the horizontal axis of the trunnion 110into the desired position.

The regulating wheel unit 111 serves as a support for a `regulatingwheel spindle which is journalled in spaced anti-friction bearings 126and 127 (Fig. 4). The regulating wheel spindle 125 supports a pair ofspaced regulating wheels 128 and 129 which are preferably adjustablysupported on the spindle 125 in a manner to be hereinafter described.

A suitable driving mechanism is provided for imparting a rotary motionto the regulating wheel spindle 125 at a relatively slow speedcomprising an electric motor 130 which is mounted on the upper surfaceof the regu- Vlating wheel unit 96. The motor 130 is provided with amultiple V-groove pulley 131 which is connected by multiple V-belts 132with a multiple V-groove pulley 133 which is supported on the drivingshaft of a variable .speed driving unit 134. The variable speed drivingunit may be any one of the various variable speed driving units now onthe market, such as, for example the Vickers speed change unit. Thedriven shaft of the unit 134 is provided with a multiple V-groove pulley135 which is connected by multiple V-belts 136 with a multiple V- groovepulley 137 which is keyed onto the right hand end ,of the spindle 125.It will be readily apparent from the foregoing disclosure that when themotor 130 is started,

a rotary motion will be imparted through the driving mechanism abovedescribed to rotate the regulating wheel spindle 125 and the regulatingwheels 128 and 129 lat a speed controlled by the speed change unit 134.The Aspeed change unit 134 is provided with an adjusting knob 138 bymeans of which the speed of the regulating wheel spindle 125 may bevaried as desired.

The spaced regulating wheels 128 and 129 are adjustably mounted on thespindle 125 to facilitate positioning the regulating wheels 12S and 129so that in any vvertical adjusted position of the grinding wheel theWork 4flanges ..140- and 141 which are screw threaded onto a spindle,125. A slidably mounted key 142 which slides .in a keyway 143 serves tolock the ange 141 in adjusted position relative to the spindle 125. Whenit is desired to adjust the regulating wheel 12S in an axial direction,the flange 140 is backed-olf after which the key 142 is moved toward theleft (Fig. 6) and the flange 141 is then screwed along the spindle 125to position the regulating wheel 128 into the desired position relativeto the annular face 65 of the grinding wheel. The key 142 is then movedtoward the right to lock the clamping flange 141 to the spindle 125after which the flange 140 is rotated to Clamp the regulating wheel 128in adjusted position relative to the spindle 125. An identicalsupporting and adjusting mechanism is provided for the regulating wheel129.

The Work rest blade 73 is preferably positioned so that the Work piecesto be ground are positioned slightly below the axis of the grindingwheel as shown in Fig. l, the regulating wheels 12S and 129 are thenadjusted along the spindle 125 so that the work piece 90 entering andleaving the grinding throat is supported by not only the work rest 73but also by the regulating wheels 128 and 129. lf it is desired to grindon the lower portion of the wheel as shown diagrammatically in Fig. 7,the wheel slide 20 is adjusted vertically so that a work piece 90resting on the work rest 73 will pass across a chord at the lowerportion of the plane annular face 65 of the grinding wheel. In thisposition of the grinding wheel, the regulating wheels 128 and 129 areadjusted in axial directions toward each other so that the work piece 90will be supported and driven by the regulating wheels as the work pieceenters and leaves the grinding throat formed by the said wheels. Theouter side faces of the regulating wheels 12S- 129 are preferablypositioned so that they are opposite to the outer periphery of the planeannular face 65 of the grinding wheel.

In setting up the grinding machine, the regulating wheel unit 95 may beswivelled in a horizontal plane about the axis of the post 105 so thatthere is a greater distance between the periphery of the regulatingwheel 29 and the plane annular face 65 of the grinding wheel than thereis between the regulating wheel 128 and the face 65, as shown in Fig. 2.With the parts in this position, the portion of the Wheel at theentering end of the work rest blade 73 rough grinds the work piece andthe other portion of the wheel face 65 finished grinds as the work piecepasses through the grinding throat. The regulating wheel unit may alsobe swivelled about the horizontal axis of the trunnion 110 bymanipulation of the screws 118 and 119 to swivel the axis of theregulating wheel spindle 125 in a vertical plane so as to produce thedesired axial feeding component upon the work piece passing through themachine.

The operation of this improved centerless grinding machine will bereadily apparent from the foregoing disclosure. Assuming that all of theadjustments to have been previously made, the motors 25 and 130 arestarted to impart a rotary motion to the grinding wheel unit 24 and theregulating wheels 12S-129. Work pieces 90 to be ground may then be movedaxially into the grinding throat where they are ground to the desiredand predetermined extent. The slide 11 may be adjusted in a horizontalplane to adjust the grinding wheel unit. Similarly the slide 95 may beadjusted transversely relative to the base to position the regulatingwheels 12S-129 into the desired position relative to the work rest blade73. After the plane annular face 65 of the grinding unit 24 is worn awaydue to grinding, the cup shape support y45 may be adjusted toward theleft (Fig. 1) to expose a fresh portion of the abrasive segments 43.

It will thus be seen that there has been provided by this invention acenterless grinding machine in which the various objects hereinabove setforth together with many thoroughly practical advantages aresuccessfully achieved. As many possible embodiments may be made of theabove invention and as many changes might be made in the embodimentabove set forth, it is to be understood that all matter hereinbefore set,forth are shown in the accompanying drawings is to be interpreted asillustrative and not in a limiting sense.

I claim:

1. A centerless grinding machine comprising a base, an adjustable slideon said base, a rotatable grinding wheel thereon having an annular planegrinding surface, means to rotate said grinding wheel at a high speed, awork rest adjustably mounted on said base extending substantiallyparallel to said annular plane surface so that the geometric projectionof its top onto said plane surface denes two separated grinding areas onthe annular surface, a regulating wheel unit including a slideadjustably mounted on said base, a regulating wheel spindle thereon,means to rotate said spindle at a speed suitable for controlling workrotation, a pair of spaced regulating wheels on said spindle to supportand rotate a work piece opposite separated grinding areas of the annularplane grinding surface and, means to swivel the regulating wheel unit ina horizontal plane about a vertical axis so that the space between theregulating Wheel and the plane surface at the work entry end is slightlygreater than the space between the other regulating wheel and the planesurface to facilitate rough grinding and then nish grinding on a workpiece as it passes axially through the machine.

2. A centerless grinding machine as claimed in claim l, in combinationwith the parts and features therein specied of means to adjust saidwheel slidevertically to vary the path of work pieces across the annulargrinding face, and means to adjust said regulating wheels axiallyrelative to each other to facilitate positioning the operativeperipheral faces of the regulating Wheels relative to the spaced activeportions of the annular face of the grinding wheel.

3. A centerless grinding machine, as claimed in claim 1, in combinationwith the parts and features therein specilied of means to adjust saidwheel slide transversely, means to adjust said wheel slide vertically tovary the path of work pieces across the annular grinding face, and meansincluding adjustable flanges on said regulating wheel spindle to supportsaid regulating Wheels to facilitate adjusting said regulating wheelsaxially relative to each other so as to position the operativeperipheral faces of the regulating wheels opposite to the separatedgrinding areas of the annular face of the grinding wheel.

4. In a centerless grinding machine, as claimed in claim l incombination With the parts and features therein specified of an arm onsaid wheel slide, an outboard bearing on said arm rotatably to supportthe end of the grinding wheel spindle adjacent to the operative annularface of the grinding wheel to facilitate a high speed grindingoperation.

References Cited in the ile of this patent UNITED STATES PATENTS1,440,639 Smith Ian. 2, 1923 1,456,462 Reeves May 22, 1923 1,924,588Addison Aug. 29, 1933 2,020,541 Ernst Nov. l2, 1935 2,229,281 EkholmJan. 21, 1941 FOREIGN PATENTS 300,808 Germany Sept. 18, 1917

